<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>JS-函数</title>
</head>

<body>

</body>
<script>
    // 定义函数1
    /*     function add(a, b){
            return a+b;
        } */

    // 定义函数2
    var add = function (a, b) {
        return a + b;
    }
    // 调用函数
    var result = add(10, 20);
    alert(result);
</script>

</html>